Simulation of heterotrophic storage and growth processes in activated sludge under aerobic conditions

In this work, an extension of the Activated Sludge Model No. 3 (ASM3) is presented which takes oxygen transfer, microbial maintenance, and biomass decay into account, in order to describe the heterotrophic storage and growth processes in activated sludge. The sensitivity of the effluent chemical oxygen demand and oxygen uptake rate to the stoichiometric and kinetic coefficients was analyzed. Model calibration was successfully performed by comparing measured and predicted values for model components. Thereafter, the model was evaluated with the experimental results of four independent case studies. Results show that the established model is able to better and mechanistically describe the heterotrophic storage and growth processes in activated sludge.